With mere intention you can choose to feel good. Perhaps going for a walk. Intend to go for a walk. Say I intend to go for a walk for 45 mins. I intend to feel good. Maybe make your environment more comfortable. I intend to create energy by cleaning my environment. If you meditate on doing these things you can eventually feel good. The brain and the intelligent universe arranges itself according to your intention. Like the placebo effect. I hope this is helpful even if it sounds completely insane.